Can anyone advise on a good item to use as 1/35 telegraph or electrical cable. I'd usually use thin lead wire but it's way too heavy for the connections on the telegraph pole. I'm thinking something like cotton thread soaked in white glue to hide the twist..?

single strands of copper speaker wire? It usually ends up looking pretty good.

Have tou ever tried EZ line? It stretches and is very thin. You could make either high tension wires or loosely hanging wire with ease.

Gary

if you have a broken battery clock or ask to some watchmaker their always change some, open the movement inside you find a coil with meters of really thin copper wire...my father in law is a watch maker and i have lots of these o nice gear ferom broken movement...really handy

Computer fans are an excellent source of very thin wire. And they break often so should be easy to get one at a repairing shop.